Derrick construction



' Nov; 14, 1933. A, w L l 1,935,095

DERRICK CONSTRUCTION File d March 7, .1932 1 2 Sheets-Sheet I ATToe/vBPatented Nov. 14, 1933 UNITED STATES PATENT OFFICE DERRICK CONSTRUCTIONArthur W. Lewis, La Canada; (Jali!., assignor to Petroleum Derrick Co.Ltd, La Canada, CaliL, a corporation of Nevada v My invention relates tooil well derricks fabricated from structural steel members. Such derricks are in general use throughout the world and are fabricated by manymanufacturers. All of these manufacturers, so far as I am aware, haveadhered closely to standard tower design, using four leg membersconnected by girts, which encircle the derricks, and diagonal crossbracing members, each member of which extends from the junction of agirt with a leg to the junction of an adjacent girt on an adjacent leg,the cross bracing members crossing each other at approximately thecenter of the panel formed by the two girts and the two legs.

In steel derricks of all kinds with which I am. familiar, including thederrick described herein, the corner legs are designed to carry theentire vertical load. In addition to this vertical load, such derricksare subjected to certain loads producing horizontal stresses in thederrick. Such stresses for example are produced by the drill pipe whichis not in use and which rests upon the derrick door and leans againstthe upper portion of the derrick. Since several thousand feet of pipe inlong stands are constantly so stored, the horizontal component of forceproduced thereby on the derrick is considerable.

In addition to this component the derrick in times of high wind issubjected to horizontal loadis eliminated and in which a novelarrangement of diagonal bracing is used. By this novel arrangement I amable to produce a derrick having the same ability to resist the forcesto which a derrick issubjected as the conventional form of derrick butin which a considerable saving in weight of material over that used inthe conventional derrick is possible due to a better utilization ofmaterial.

In derricks of my invention the diagonal members are also depended uponto resist the horizontal load components imposed on the derrick, butthese diagonal members are in compression. Derricks constructed inaccordancewith my invention are not only more economical in materialusedin their construction than conventional derricks but are much morerigid, due to the open 'showing'the preferred form of derrick embodyingmy invention.

Fig. 2 is an elevation of side of said derrick.

Fig. 3 is an elevation of the calf wheel'side of said derrick.

Fig. 4 is an enlarged view showing one method of connecting the variousderrick members.

Fig. 5 is an elevation showing a center six point connection.

Fig. 6 is a view showing a corner six point diagonal connection as itwould appear were that portion of the structure shown to the left of theline a--a turned 90 towards the plane of the paper from its actualposition.

Fig. 7 is a section through one of the legs.

Fig. 8 is a section taken as indicated by the line b--b of Fig. 6;. thisfigure, however, is not distorted from its normal plane.

In the drawings I have illustrated a derrick of the proportions usuallyemployed in well drilling rigs, the derrick having four sides and beingsubstantially larger at its base than at its upper end. I haveillustrated a construction suitable for a derrick in the neighborhood of120 feet so high and intended to carry various units of drillingequipment, such as a crown block, drawworks, etc.

The derrick illustrated, being four-sided, includes four legs 10. Inaccordance with the present invention, horizontal girts 11 are providedat each side of the derrick to extend between. the legs 10, diagonalmembers 12 are provided between the girts 11 and the legs 10, andvarious other features of construction are provided, as will behereinafter described.

The legs 10 of the derrick are located at the corners of the structureand extend from the base 1 to the upper end. Each leg 10, in accordancewith my invention, involves three principal parts, namely, two mainflanges 13 lying in the planes of the adjoining sides of the derrick,and an outer flange 14 projecting outwardly from the point ofintersection of the main flanges 13. The

theladder and pump -'main flanges together form an angle-shapedstructure, each main flange for a part to which the girts and diagonalmembers of the structure may be connected. The outer flange 14 projects.outwardly from the corner formed by the main flanges so that there areequal angles between the outer flange and the two main flanges,'asclearly illustrated in Fig. 'l of the drawings. The outer flange 14,because of its relationship to the main flanges, adds a sub stantialamountof strength and rigidity to the leg by the addition of but littlematerial to the structure formed by the main flanges alone.

In accordance with the preferred form of the invention, each leg is ofsectional construction, 1. e., the legconstruction just described is intwo sections, the line of division being through the center of the outerflange 14: in the plane of the outer flange, so that each leg sectionincludes a main flange and an outer flange part 14. When the leg isassembled, as shown throughout the drawings, the flange parts la abutand are secured together as by bolts 15, or the like. In

practice, bolt holes are provided at suitable in-.

tervals throughout the lengths of the flange parts 14 and the bolts 15are applied to secure the flange parts 1 together as the derrick is assembled. A feature of the sectional leg construc= tion just described isthat the sides of the der= rick can be assembled on the ground insections of suitable length and then moved into position to be securedby coupling the flange parts 14 of the legs through the bolts 15.

In the structure of the present invention, there are several horizontalgirts 11 at each side of the derrick. The girts 11 are arranged toextend between opposing main flanges 13 of the derrick legs and arevertically spaced. The girts 11 may be formed of angle iron and may beconnected to the main flanges 13 of the legs through joints orconnections such as I will hereinafter describe.

The invention provides a novel and eflective arrangement of diagonalmembers 12 between the legs 10 and horizontal girts 11. In accordancewith the invention, there are four diagonal braces located in each spacedefined by adjacent legs of the derrick and adjacent girts 11 extendingbetween said legs. The diagonal members 12 are connected to the opposingmain flanges 13 of the said derrick legs at points intermediate thepoints of connection between the horizontal girts and the legs. Diagonalmembers A extend from their point of connection with the derrick legsupwardly and inwardly to a point where they adjoin each other andconnect with the middle portion of the upper girt 11, while diagonalmembers B extend from their point of connection with the legs downwardlyand inwardly -to a point where they adjoin and connect with the lowergirt 11. This arrangement of parts is clearly illustrated in Figs. 1, 2,and 3 of the drawings. The diagonal members A and B are preferablyformed of angle iron and are connected with the leg flanges and thegirts through connections such as I will hereinafter describe. In thecase illustrated, the diagonal members are shown connected directly tothe leg flanges 13 and are shown connected to gusset plates 16 attachedto the horizontal girts by bolts 17. The diagonal members 12 of theconstruction are active or load-carrying parts of the structure and,when the derrick is under a strain, these members act either undercompression or tensiofl. By supporting the diagonal members 12intermediate their ends, a given load capacity can be gained by the useof lighter members than aesaecs the diagonal members and extend topoints ad- 3 jacent the points of connection between the horizontalgirts 11 and the legs 10.

It is to be noted that the braces 18 that may be employed to permit ofthe use of light diagonal members are comparatively short and form. buta small portion of the derrick structure.

The framing and bracing at the lower part of the derrick may varyconsiderably from the main derrick construction that I have hereinabovedescribed in order to accommodate equipment such as may be employed inconnection with the derrick. In the drawings, I have shown framing belowthe horizontal girts C suitable for .units or? equipment such as arecommonly employed in the drilling of oil wells.

My present invention provides a joint or con nection for coupling theends of the angle iron members with the other parts, for instance, withthe leg flanges and the gusset plates. In accordance with my invention,a reinforcing member 20 is applied to the end portion of the angle iron,being connected to the member, and a bolt 21, or the like, connects thereinforcing member and one flange of the angle iron to the member towhich the angle iron is connected, while a bolt 22 connects thereinforcing member with the other flange of the angle iron. Thereinforcing member may be an angle-shaped part designed to flt into theangle iron and having flanges 23 fitting against the inner sides of theflanges of the angle iron. The main connecting bolt 21 which joins the.angle iron to the member to which it is to be connected joins twoflanges and the reinforcing member to the angle iron. The bolt 22 joinsthe other flange of the angle iron to the other flange 23 of thereinforcing member. Through the medium of the reinforcing member and thebolts 21 and 22, the second or otherwise unsupported flange of the angleiron is connected with the member to which the angle iron is con=nected, thus developing the strength of both flanges of the angle iron.In addition to the bolt 21, the reinforcing member 20, the angle, andthe member to which the angle iron is connected may be connected througha lug 2% formed on one 1 ltl flange 23 of the reinforcing member toproject of the derrick can be assembled on the ground and lifted intoplace, where they may be made secure by the bolts 15 joining the flangeparts 14 of the leg sections. It is to be noted that the outwardlyprojecting flange parts 14 are angularly disposed so that a side sectionof the derrick can be readily moved inwardly into position so that it isguided by the flange sections 14 of the adjoining sides of the derrickand that the leg parts requiring connection, 1. e., the flange parts is,are located so that the bolts 15 can be readily applied.

It will be noted that the diagonal members 1122 form six point (ormember) connections at the points indicated by the dotted circles at weand 101 in Fig. l. The connections at point 100 are shown in Fig. 5, andthe connections at point 101 are shown in Fig. 6.

Referring to Fig. 5 it will be seen that forces are distributed from thepoint 102 in six direc tions, due to the six members which radiate 'iZrothis point (the girt i1 acting as two of these members).

Referring to Fig. 6 it will be seen that forces are distributedfrom thepoint 103 in six directions, due to the six members which 1'11:- fromthis point (the leg is acting as two of these members).

The derrick in fact consists of legs and (lieg onal members, each of thediagonal members terminating at each end in a six point connection.

ese diagonal members difier from the corn ventional cross bracingfoundin all sorts of strnc= tures in that they act in compression toresist horizontal forces.

It will further be noted. that in the embodiment of my invention, asshown in Fig. 6, the diagonals of one side are definitely positionedwith relation to the diagonals of an adjacent side, that is all thediagonals at one end or the other terminate at a six point connectionwhich is de up of the legs, two diagonals from one side and twodiagonals from another side. This six point system or bracing givesgreat stifiness to the derrick with a um use of material.

I claim as my invention:

i. In an oil well derrick, the combination of:

iour leg members; girt members arranged in sets of four extending aroundthe-derrick in the same plane and being connected at their ends to saidlegs; and diagonal members each extending from and connected toadjacentlegs, said diagonal members being so placed that they form with thegirts six point connections at the centers or said girts and that theyform with the legs six point connections on said legs at a point midwaybetween the planes oi adjacent girts.

2. In an oil well derrick, the combination of: tour leg members; giltmembers arranged in sets or tour extending around the derrick; in thesame plane and being connected at their ends to said legs; diagonalmembers each extending from and connected to adjacent legs, saiddiagonal inexn= hers heing'so placed that they form with the sirts sixpoint connections at the centers of snid. sirts and that they form withthe legs sis: point connections on said legs at a point midway betweenthe planes of adjacent girts; auxiliary hraces substantiallyperpendicular to said diagonal members, each of said braces extendingfrom the junction of a girt with a leg to a point on 'a diagonal bracemidway between thegirt and the leg; and means for securing one end ofsaid brace to said leg and the other end oi said brace to said diagonalmember.

, ARTHUR Wu Hit

